Peter A Goldsbury
I do not think that Szczepan's 'old saying' should be dismissed so lightly.
I had a similar argument once with no less a shihan than Kazuo Chiba. Chiba Sensei's aim in creating his Birankai has been to create good teachers and he strongly believed that a lifelong commitment to an art like aikido was foolish unless the student found the teacher that 'fitted'. Chiba Sensei himself came across one of Kisshomaru Ueshiba's early books in a bookstore, saw what he had to say about O Sensei, and decided that O Sensei was the teacher for him. He sat outside the Hombu Dojo for three days and rest, as they say, is history.
My argument was that Chiba Sensei was young and 'foolish' at the time (though I did not put it quite in these terms) and had not yet made any decisions about what to do with his life. For those who had made such decisions, it was far too harsh to expect them to organize their entire future aikido existence around one teacher.
Both Chiba Sensei and myself were assuming that the student had made a lifelong commitment to aikido and that the keynote of this commitment was continuous, hard, daily training, not occasional appearance at seminars. Chiba's argument was based on his own experience; mine was based on mine. In fact my own lifelong commitment to aikido was largely formed as a result of training with him as teacher. Both views assume that you need a teacher who has the capability to take you further on the Way, if you like, than you think you can go yourself.
Best wishes to all,
Also, in short term, from strictly technical point of view, if a student learns from bad teacher, he will develop many bad habits. These habits will be very difficult(if not impossible!) to erase, even for very talented teacher - it will take much longer to erase then to teach the new, good one. So we may say, that the time, effort an money with bad teacher are lost for nothing and worse - you go under zero.